Centerless grinding device



April 1951 F. J. STEVENS 2,547,290

CENTERLESS GRINDING DEVICE Filed June 11, 1948 3 Sheets-Sheet 1INVENTOR.

' "1 1 3 ER w h franl'dli'ferens,

April 3, 1951 F. J. STEVENS 2,547,290

CENTERLESS GRINDING DEVICE Filed June 1 1, 194s 5 Sheets-Sheet 2INVENTOR. j ranlvllszeyek s',

April 3, 1951 F. J. STEVENS CENTERLESS GRINDING DEVICE 3 Sheets-Sheet 3Filed June 11, 1948 INVENTOR. fianZJSZeyens,

Patented Apr. 3; 1951 CENTERLESS GRINDING, DEVICE .1. Stevens,NutIey,-N. J. Application .l'inieru, 1948, Sefi&l-N0. 32,434 eciaims.(01.51- 1 08 v Thisinvention relates toran 'improvementin a eenterlsssgrindi ng device and more particularly to a type thereof :arrianged tooperate 4011 in sula'tor bodies.

'object of the ipresent invention is thefiprovision of an improvedcentei'less grinding device wherein cylindrical :blan-ks may thefed-continuou'sly to the .action "of .a cutting means :for .jgradu allyrand progressively pr'ofiling the cylindrical blanks. I

Another object "of :the invention is .fthe :provision, in a 'cen'terlessgrinding device, of ;a' work support shaving aassocialted a :workcontacting means :to control the .movement :of the work :pieees throughthe support.

A further object :of the invention the provision .of :an improvedicenterless grinding .device whereina cutting -origrinding means is:arranged 'ccentrically "with irespedt :to the gpath (of "work pieces so:as to .progressively profile the work pieces.

:The above andinunierousrother -.ob.iects act .the invention will:become apparent from .the .succeeding description sconsi'dered togetherwith the accompanying drawings, "wherein:

Figure :1 isaaiplan yiew'rofan improved-reenter less grinding edevieeembodying the ipresent sinventihn.

T Figure ":2 i is Pa rfront zelevational viewof the :improvedicenterless @grindmg device :shown in .Figure 1.

-Figure is J- a vertical t'sectional view taken along the dines-343 :of.iigure 2, docking in 'the direction ref thearrows.

Figure 4 is a sectional view .ta-kentalongithe lines IA-+4 of i Figure3, looking -.in the direction of the arrows.

l igurezfiiis can end elevational .view aofya-nylinflricaliblank typicalf a work piece which may belzprofiled -by the device .0f uthB present:inven-' -tion.

Figure '16 is ian enil elevational "view of 2, ;,profiled w ork. pieceafter :its :dis'charge =.from .theidevice :and. illustrative :lOf the;:profi1ing which email be zefiected @by the device.

Referring now :.in detail :to :the drawings, wherein ilike referencecharacters .indicate .like fpartsxthe fnumeral I .is emp10yed todesignate, in htsomewhatigeneral manner, a centerless grinde ing devicecharacteristic of 1' the v present invention. The ccnterlesssrindingdevice -.comprises eaibed plate :or 'platform'i-zwhich; ifdesired, mayhave at its corners the usual standardsH-legscor supports .to maintainithe gplatform 1111 319.vatedipositionizor.easrwillebesunderstood,etheebed I plate may be;-p1a,c ;d on a sui bl oundatien :89

as to maintain it in a fixed position. Mounted upon the bed plate is aslide or auxiliary mountins iplate dprovided 'iv-ithsuitable kerf s toaccommodate' keys :5 .tormi-ng a part of the platform and thus theauxiliary mounting plate is interlocked with the bed ,plateliowever-.arranged to .move lon itudinally .relative thereto for the purpose to:be :made hereinafter apparent. Ellie slide ghas, ;a.t @118 end thereof,an upstanding apertured wall -6 wh chmax, as e ined, e ade integraltherewith by any means r method 5. long as .it becomes a part of h sliMounted upo What a be termed th ti side-race 'hof thesslide wall ,is awork piece sup- P0133 01 guide sring i8- vThis uide .ning. 10 Qu ted orannular forniation. may be secured .to the slide wall by any meansstnonesshqwn) solong as it .is made removable since the illustratedguide ring is -.,only characteristic. of a. .type which may be useddepending entirely upon itheutype of work-pieces .used and .theparticular profiling desired. ,The work .piece support has at its lipperlimits orin pmximity thereto ,a .feed .ordelivery chute 9 which is inV-thenature; of ya tubular member communicating with the vinterior orthe work -,p'ie c.e .support. A mower .01 any such means not-shown) zmaybe associated with the delivery chute to feed or .supply ;a' pont'inuqusstream {of work pieces L0 -...to the delivery {211111 9 and the glatteris made .offsuch configuration in section in eorder to accommodateeaseries of superimposed work .pieces. ,As ;previously ;.in dicated, the.work pieces ,used .with the ,p11e sent structure .are Characterized .by.the cylindrical blank 1;: shown .in .Eigune v5110f the. drawings andthis .blankzis preferably {made of .ceramic material. The :blank pieces.,are r-p fefera ly :formed by the extrusion .proces so,r v.any othermethod well known .or commonly .used Joy the ceramic industry..iAlso-itemay -.be -.well.t,0 stateheregthat the completed; componentprwork piece l .2,.il1 u's- .trated-in Figure .6 of .thedrawing has beenprofiled-:as idesired. --with .a-kerf .oneroov-e 4 3 o med inithegpcriph r-y thereof t adapt .th .sruoved blan'klto .beusedasaninsulator or .Jous'hing.

:The .support .or .guide -,.ring-, stationary -.with respect .to ;the:s1ide, .is .;.of substantially cihannel shape in -,cr,oss .section. as@clearl-y .illustrated in FigUIKE A'TOf the. drawings .and. as .-.-s11;h.- lmt .0n as a .racewaysfor .the I.accommodation of a cpn.tinuoussiiowiof .blank'sethenethwueh 1Tb dc rin compris s .a ba ku .91irccula sh arin wanIAQhfiV QEeZataQQ iedgajthetcefsaninwardly directedconfining .iflanse .115 terminating in reentrant flange it which isparallel with and spaced a predetermined distance from its companionbearing wall. The other edge of the back-up wall merges with a short,circular retaining flange l! which is parallel with but shorter than itscompanion confining flange IS. The distance between the flanges l and l!and the distance between the wall 14 and flange 16 are such as to neatlyaccommodate and confine the blank II and allow the latter to progress ina true path along a given course within the support. As will be notedthe bearing wall is provided with an opening as at l8 to allow theblanks entrance to the support as clearly illustrated in Figure 3 of thedrawings. It is to be further noted that while the feed chute is illusbealigned or associated with pulleys to develop trated at the top of thestationary support, the

relationship between the flanges l6 and I1 is such that the blanks willbridge the distance therebetween and thus prevent the blanks movingother than in the predetermined course in the support.

Substantially diagonally disposed from the feed chute is a dischargechute l9 formed by a tangential extension'of the circular bearing wallat (see Figure 3). This arrangement 20 of the bearing Wall presents anopening 2| in the support so that as the worked pieces enter thisopening they are then free to roll out of the confines of the support toa container (not shown) disposed in a receiving position below thedischarge chute. For the extent 'of the opening 2| the flanges l5 and l!are extended downwardly to present sides 22 of the discharge chute.

In order to control not only the flow of blanks into the stationarysupport but also to control the movement of the blanks from the feedchute to the discharge'chute there is associated with the stationarysupport, a cage or holding means 23 formed by a disc 24 havingoutstanding normally therefrom a plurality of equally spaced pins,fingers or studs 25. The studs are such that they extend into thestationary support through the short retaining flange side thereof andsince the disc is arranged to rotate about an axis coincident with thecenter of curvature of the support the pins'will maintainat all times aconstant relation with the wall and flanges ofthe stationary support. Aswill be noted from the drawings, the blanks are stacked above oneanother in the feed chute and. as the disc rotates in a clockwisedirection as viewed in Figure 3, a single blank I la will drop into thestationary support between adjacent fingers and the next upper blank llbwill be retained in the feed chute until the space between the nextadjacent fingers reaches a point beneath the feed chute and then blank Ilb will drop thereinto. Thus a continuous and controlled flow of blanksenter the stationary support to be worked onas hereinafter described.Some control must be provided for the disc and toward the accomplishmentof this function the slide, off to one side of the disc, has mountedthereon an electric driven motor 26 having mounted on a shaft thereof adouble pulley 21. Positioned adjacent to the motor is a box 28containing a set of reduction gearing (not shown) with dual oroppositely disposed shafts 29 and 30 extending therefrom. The shaft 30is provided with a double pulley 3| which isin alignment with the motorpulley 21 and the motor and gearing pulleys are connected by anendlessbelt 32. Thu; force is transmitted from themotor to the reductiongearingI 'The purpose ofthe double pulleys is obvious, inthat since themotor'employed is of constant speed the belt may extending axiallytherefrom, a hub 33 sleeved over the gearing shaft 29 and removablysecured thereto so that the disc will move or rotate in response to theaction of the gearing shaft 29.

The profiling means for cutting or grinding the blanks is characterizedby a wheel 34 which is of such a diameter to enter the confines of thestationary support through its aperture. Any suitable type of grindingwheel may be used or a plurality of spaced wheels may be housed withinthe support depending entirely upon the profiling design desired.

The grinding wheel is so disposed within the confines of the stationarysupport that its axis is spaced slightly from the axis of the disc or,in other words, the grinding wheel forms what may be termed an eccentricpattern with respect to the cage fingers or the stationary support.Because of this arrangement the periphery or outer surface of thegrinding wheel gradually approaches the back-up Wall l4 of thestationary support. Since the distance between the grinding wheel andback-up wall gradually diminishe between the location of the feed chuteand location of the discharge chute the grinding wheel is thereforearranged to cut into-the blanks as they progress between these twolocations so that as the blanks pass the approximate point or stationmarked He in Figure 3 the profiling or grinding operation is completed.Further it will be noted that as a blank such as I la enters thestationary support it is held out of contact with the grinding wheel andit is not until the blank I la reaches the station lid that the blank iscontacted by the grinding Wheel. At this station lld the blank is alsoin contact with the back-up wall M of the stationary support andprofiling of the blank starts and is completed when the blank reachesthe approximate position of the station He. By way of a more specificexample in devices now in use embodying the present invention the cageis arranged to rotate at a speed of five revolutions per minute and thegrinding Wheel is arranged to rotate in the same direction at a rate ofapproximately thirty-six hundred revolutions per minute. It is believedthat the frictional value of the line contacts between the fingers andblanks and the back-up wall and blanks is less than the force of thecontact between grinding wheel and blank and therefore while the cageacts as a retarding medium the grinding wheel completely profiles theblanks approximately between the stations lid and H0.

Since the grinding wheel is fixed longitudinally of the platform theslide is made adjustable longitudinally of the platform so that not onlymay the grinding wheel be withdrawn from the support to change the wheelafter it has Worn beyond a permissible degree but also to position thegrinding Wheel longitudinally of the device so that the profiling of theblanks may be located as desired. Toward the accomplishment of thisfunction one end of the bed plate is provided'with an upstanding barrier35 which has journaled therein a rotatable screw 36 arranged to bemanipulated by a hand wheel 31. The screw extends longitudinally of thedevice through a suitable block 38 forming a part of the slide andbecause of this arrangement any manipulation of the hand wheel will movethe slide axially of and relative to the grinding wheel.

The grinding wheel is mounted on a shaft 39 of 76 a suitable electricmotor 40 and as viewed particiilarly in fl ligure .:-,3 iofathexdrawing:also t-rotates the. -same direction'rasathescage, namely, clock!- wise.Functioning as :a carrier for -i-the grinding "wheel motor :is aninverted channel section 42! leaving "the motor 40 securely anchoredthereto intermediate the ends thereof. Disposed immediately beneath .themotor carrier is .a similar channel section or movableor slidable rest42 which bears somewhat freelyupon the platform and is there r movablehiftable relative i:

Jex'tenils throughsuitable apertures in the motor carrier and thus thelatter is :pivotally connected tothe slidablefrest and arranged to bepivoted vertically about a horizontal axis. Removed from the pivotalconnection last referred to is an adjusting screw 45 having a threadedinterlocking relation with the motor carrier. This screw has one endabutting the subjacent slidable rest and its upper end supplied with anoperating wheel 46 so that upon a proper manipulation of this lastnamedoperating wheel the motor carrier will be pivoted about its journaland the grinding wheel will be moved vertically to accomplish theparticular cut or profiling desired. When the grinding wheel becomesworn or if the depth of cut need be corrected a proper manipulation ofoperating wheel 46 will set the grinding wheel at a proper or desiredlocation.

A third adjustment is believed necessary in the device to properlyposition the grinding wheel and compensate for wear which is inevitablein a grinding wheel. This third adjustment should move the grindingwheel transversely of the device and accordingly the bed plate isprovided with a pair of parallel 01' longitudinally spaced keys orshoulders 47. These keys occupy neatly, suitable grooves 48 in theslidable rest to thereby arrange for the guidance of the slidable restand its carried components transversely of the bed plate. Disposed alongwhat might be termed the leading edge of the bed plate is a barrier 49having journaled therein a screw supplied with an operating wheel 5|.The screw 50 is threadedly related with a leg 52 upstanding from theslide plate and accordingly any rotative action of the operating wheel5| will result in moving the grinding wheel forwardly or rearwardly.

From the above it will be noted that various changes and alterations maybe made to the illustrated and described construction without departingfrom the spirit of the invention and scope of the appended claims.

I claim:

1. In a centerless grinding device, the combination of, a plate, acurved support carried by said plate and having spaced feed and outletchutes arranged respectively to receive and discharge cylindricalblanks, a cage carried by said plate and arranged to rotate about anaxis coincident with a center of curvature of said support, meanscarried by said plate for rotating said cage, means on said cageextending into said support and arranged to control movement of saidcylindrical blanks along said support, a grinding wheel within theconfines of said support and driven at a greater speed than said cage;an axis of said grinding wheel being spaced from said axis of said cageso that as said cylindrical blanks approach Said discharge chute thedistance between said 6 iggrindingwwheel and support W111 gradually;de'1- .cr.ease, and means for :moving .said plate toward and away fromsaid grinding wheel.

12.iIn 2a rcentei'lless grinding :device, the :combination of, a plate,a curved support mounted --'on said plate :and having .spac'ed feed and:outlet .chutes :arranged respectively to receive and dis- -=-cha-rge:cylindrical blanks, a cage carried :by said :plate and arranged torotate about an axis coin- .c'ident withzarcenter of curvature of saidsupport, fingers carried by said page extending intoconfines of said.support and arranged to control movement of .said cylindrical blanksalong said support, .a grinding whee1 .of "less :diameter than ssaidcage and within the transverse limits :of' said fingers, said grindingzwheel being driven :at a speed inlexcessrof said :cage :rotation, saidgrind- --ing wheel :forming an eccentric pattern :withzsaid cage so thatthe distance between a periphery of said grinding wheel and said supportwill gradually diminish from said feed chute to said outlet chute, andmeans for moving said plate toward and away from said grinding wheel.

3. In a centerless grinding device, the combination of, a plate, astationary support mounted on said plate and having spaced delivery andoutlet chutes arranged respectively to receive and discharge acontinuous flow of cylindrical blanks, a movable cage carried by saidplate and having a plurality of spaced means extending into the confinesof said support for controlling movement of said cylindrical blanksthrough said support, movable grinding means in radial alignment withsaid cage and support and having a portion only thereof extending intothe limits of said support short of said cage means; a periphery of saidgrinding means gradually approaching a back-up wall of said support assaid cylindrical blanks approach said outlet chute so that saidcylindrical blanks will bear against said back-up wall as said grindingmeans profiles said cylindrical blanks, and means for moving said platetoward and away from said grinding means.

4. In a centerless grinding device, the combination of, a plate, astationary support carried by said plate and having spaced delivery andoutlet chutes arranged respectively to receive and discharge acontinuous flow of cylindrical blanks, a movable cage spaced from saidsupport and having a plurality of spaced fingers extending into confinesof said support for the control of said cylindrical blanks through saidsupport, said movable cage being carried by said plate, movable grindingmeans having a portion only thereof extending into the limits of saidsupport and arranged to move at a rate greater than the rate of movementof said cage fingers; said grinding means forming an eccentric patternwithinsaid support so that said grinding means will gradually cutintosaid cylindrical blanks as the latter approach said outlet chute,and means for moving said plate toward and away from said grindingmeans.

5. In a centerless grinding device, the combination of, a, stationaryannular support for carrying cylindrical blanks andlprovided' with adelivery chute and a discharge chute, driven means at one side of saidsupport having fingers extending into said support for the control offlow of cylindrical blanks from said delivery chute to said dischargechute, and cutting means driven at a greater speed than said drivenmeans, a single means for moving said support and driven means laterallytowardand away from said cutting means, said cutting means being mountedeccentrically with respect to said annular support so as to urge saidcylindrical blanks against said support and gradually profile saidcylindrical blanks as the latter approach said discharge chute.

6. In a centerless grinding device, the combination of, a stationaryannular support for carrying cylindrical blanks and provided with adelivery chute and a discharge chute, driven means at one side of saidsupport having fingers extending into said support for the control offlow of cylindrical blanks from said delivery chute to said dischargechute, cutting means driven at a greater speed than said driven means, asingle means for moving said supportand driven means transversely towardand away from said cutting means, said cutting means being mountedeccentrically with respect to said an- REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date.

993,981 Grover May 30, 1911 1,999,321 Dunham Apr. 30, 1935 2,048,265Hatebur July 21, 1936 2,397,459 Armbrust Apr. 2, 1946

